Android example source code file (VisibilityCallback.java)

This example Android source code file (VisibilityCallback.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

activity, android, attributeset, button, debug, monitoredtextview, override, ui, util, utilities, utils, view, visibilitycallback, widget

The VisibilityCallback.java Android example source code

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.view;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.TextView;
import com.android.frameworks.coretests.R;

import android.os.Bundle;
import android.widget.Button;
import android.view.View;
import android.app.Activity;

/**
 * Exercise View's ability to change their visibility: GONE, INVISIBLE and
 * VISIBLE. 
 */
public class VisibilityCallback extends Activity {
    private static final boolean DEBUG = false;

    private MonitoredTextView mVictim;
    
    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.visibility_callback);

        // Find the view whose visibility will change
        mVictim = (MonitoredTextView)findViewById(R.id.victim);

        // Find our buttons
        Button visibleButton = (Button) findViewById(R.id.vis);
        Button invisibleButton = (Button) findViewById(R.id.invis);
        Button goneButton = (Button) findViewById(R.id.gone);

        // Wire each button to a click listener
        visibleButton.setOnClickListener(mVisibleListener);
        invisibleButton.setOnClickListener(mInvisibleListener);
        goneButton.setOnClickListener(mGoneListener);
    }


    View.OnClickListener mVisibleListener = new View.OnClickListener() {
        public void onClick(View v) {
            mVictim.setVisibility(View.VISIBLE);
        }
    };

    View.OnClickListener mInvisibleListener = new View.OnClickListener() {
        public void onClick(View v) {
            mVictim.setVisibility(View.INVISIBLE);
        }
    };

    View.OnClickListener mGoneListener = new View.OnClickListener() {
        public void onClick(View v) {
            mVictim.setVisibility(View.GONE);
        }
    };

    public static class MonitoredTextView extends TextView {
        private View mLastVisChangedView;
        private int mLastChangedVisibility;

        public MonitoredTextView(Context context) {
            super(context);
        }

        public MonitoredTextView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        public MonitoredTextView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }

        public View getLastVisChangedView() {
            return mLastVisChangedView;
        }

        public int getLastChangedVisibility() {
            return mLastChangedVisibility;
        }

        @Override
        protected void onVisibilityChanged(View changedView, int visibility) {
            mLastVisChangedView = changedView;
            mLastChangedVisibility = visibility;

            if (DEBUG) {
                Log.d("viewVis", "visibility: " + visibility);
            }
        }
    }
}